President Trump calls it a "Witch Hunt," but the Justice Department on Friday strongly defended special counsel Robert Muellers probe into Russias involvement in the 2016 election.

On the same day that House Republicans, backed by Trump, released a memo intended to discredit the investigation, the Justice Department told a federal judge that Mueller "is properly operating within the scope of his authority."

The defense came in legal papers urging a federal district court here to dismiss former Trump campaign chairman Paul Manaforts lawsuit challenging his indictment on conspiracy and money laundering charges.

Manafort alleged that Mueller exceeded his authority and that Deputy Attorney General Rod Rosenstein — facing possible ouster by a fuming Trump in the wake of the memos release — granted the special counsel "carte blanche to investigate and pursue criminal charges in connection with anything he stumbles across."

"These claims lack merit," Justice Department lawyers said in a 35-page response filed Friday night. "The appointment of the Special Counsel was squarely within the Acting Attorney General’s authority and consistent with the Department’s Special Counsel regulations.

"The Special Counsel is properly operating within the scope of his authority, including with respect to Manafort’s ongoing criminal prosecution."

While the Republicans four-page memo doesnt address Mueller directly, it attacks the FBI for omitting information when it asked a Foreign Intelligence Surveillance Court for authority to monitor a former Trump campaign aide suspected of Russian ties. And it accuses Justice Department officials of bias against Trump.

Trump used the memos release Saturday to tweet that it vindicates him in the Mueller probe, which he called "an American disgrace."

But on "Fox and Friends," White House principal deputy press secretary Raj Shah said Rosensteins "mistake" should not lead to his firing. "We want him to continue his role," Shah said.

The Justice Department apparently disagrees with Trumps assessment of the Russia probe. It quotes Rosensteins testimony to Congress two months ago, in which he said: “I can assure you that the special counsel is conducting himself consistently with our understanding about the scope of his investigation.”